1. Field of the Invention
The invention relates in general to electrical switches and actuators therefor which are arranged for relative movement, requiring precise relative positioning for proper switch operation.
2. Description of the Prior Art
Certain types of applications for electrical switches require that a switch operate to indicate positional relationship of a moving object relative to a stationary object. Thus, the electrical switch and actuator therefor are mounted for relative movement, with either the switch or actuator being carried by the movable object. The other element of the combination is mounted on the stationary object.
A typical application for such a switch/actuator arrangement is for the translating device used in elevator systems for detecting the position of an elevator car in its hoistway. The elevator system requires this positional information in order to properly control the operation of the elevator car, or cars. Examples of such switch/actuator arrangements include (a) an arrangement for producing a light beam which is interrupted by an actuator, (b) mechanical switches with cam followers which are operated by a cam actuator, (c) a magnetic switch in the form of an inductor relay, with the inductor relay having an incomplete magnetic circuit, which is completed by an actuator in the form of a plate or vane constructed of magnetic material. Close proximity of the magnetic switch and vane completes the magnetic circuit to operate the switch, and (d) magnetic switches, such as reed switches, which are operated from one position to another position while being subjected to a magnetic field, such as from a permanent magnet actuator. All of these arrangements require accurate positioning and alignment of the various elements for proper operation, with the magnetic switch/actuator arrangements requiring perhaps the most precise positioning, especially when the switch is operated through a flat non-magnetic cover by a flat magnetic plate actuator member. This latter arrangement requires both the spacing and angular positioning of the two flat surfaces to be precisely adjusted. This adjustment between the magnetic switch, which is usually mounted on the elevator car, and the magnetic vanes, which are usually mounted in the hoistway, is thus very tedious and time consuming, and it would be desirable to provide a new and improved switch/actuator arrangement which permits quick and precise adjustment of the relative positions of these two components.